Right from the first sentence this is a load of @*#$!!
“When you go to a bar in Japan…”
really? any bar? just pick one at random?
“all of their ice in Japan is crystal clear”
really? all of it? doesn’t matter where i go?

Or you could just refrigerate the bottle and the glasses, thereby getting the whiskey down to the desired temp without adding any melt-water at all. Every Joe Sixpack who keeps a few mugs in the freezer is on to it.